/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.sun.org.apache.xml.internal.resolver.readers;

import java.util.Vector;

import com.sun.org.apache.xml.internal.resolver.Catalog;
import com.sun.org.apache.xml.internal.resolver.Resolver;
import com.sun.org.apache.xml.internal.resolver.CatalogEntry;
import com.sun.org.apache.xml.internal.resolver.CatalogException;

import org.xml.sax.*;
import org.w3c.dom.*;

/**
 * Parse Extended OASIS Entity Resolution Technical Committee
 * XML Catalog files.
 *
 * @author Norman Walsh
 * <a href="mailto:Norman.Walsh@Sun.COM">Norman.Walsh@Sun.COM</a>
 * @see Catalog
 */
public class ExtendedXMLCatalogReader extends OASISXMLCatalogReader {
    /**
     * The namespace name of extended catalog elements
     */
    public static final String extendedNamespaceName = "http://nwalsh.com/xcatalog/1.0";

    /**
     * The SAX <code>startElement</code> method recognizes elements
     * from the plain catalog format and instantiates CatalogEntry
     * objects for them.
     *
     * @param namespaceURI The namespace name of the element.
     * @param localName    The local name of the element.
     * @param qName        The QName of the element.
     * @param atts         The list of attributes on the element.
     * @see CatalogEntry
     */
    public void startElement(String namespaceURI,
                             String localName,
                             String qName,
                             Attributes atts)
            throws SAXException {

        // Check before calling the super because super will report our
        // namespace as an extension namespace, but that doesn't count
        // for this element.
        boolean inExtension = inExtensionNamespace();

        super.startElement(namespaceURI, localName, qName, atts);

        int entryType = -1;
        Vector entryArgs = new Vector();

        if (namespaceURI != null && extendedNamespaceName.equals(namespaceURI)
                && !inExtension) {
            // This is an Extended XML Catalog entry

            if (atts.getValue("xml:base") != null) {
                String baseURI = atts.getValue("xml:base");
                entryType = Catalog.BASE;
                entryArgs.add(baseURI);
                baseURIStack.push(baseURI);

                debug.message(4, "xml:base", baseURI);

                try {
                    CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
                    catalog.addEntry(ce);
                } catch (CatalogException cex) {
                    if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
                        debug.message(1, "Invalid catalog entry type", localName);
                    } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
                        debug.message(1, "Invalid catalog entry (base)", localName);
                    }
                }

                entryType = -1;
                entryArgs = new Vector();
            } else {
                baseURIStack.push(baseURIStack.peek());
            }

            if (localName.equals("uriSuffix")) {
                if (checkAttributes(atts, "suffix", "uri")) {
                    entryType = Resolver.URISUFFIX;
                    entryArgs.add(atts.getValue("suffix"));
                    entryArgs.add(atts.getValue("uri"));

                    debug.message(4, "uriSuffix",
                            atts.getValue("suffix"),
                            atts.getValue("uri"));
                }
            } else if (localName.equals("systemSuffix")) {
                if (checkAttributes(atts, "suffix", "uri")) {
                    entryType = Resolver.SYSTEMSUFFIX;
                    entryArgs.add(atts.getValue("suffix"));
                    entryArgs.add(atts.getValue("uri"));

                    debug.message(4, "systemSuffix",
                            atts.getValue("suffix"),
                            atts.getValue("uri"));
                }
            } else {
                // This is equivalent to an invalid catalog entry type
                debug.message(1, "Invalid catalog entry type", localName);
            }

            if (entryType >= 0) {
                try {
                    CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
                    catalog.addEntry(ce);
                } catch (CatalogException cex) {
                    if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
                        debug.message(1, "Invalid catalog entry type", localName);
                    } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
                        debug.message(1, "Invalid catalog entry", localName);
                    }
                }
            }
        }
    }

    /**
     * The SAX <code>endElement</code> method does nothing.
     */
    public void endElement(String namespaceURI,
                           String localName,
                           String qName)
            throws SAXException {

        super.endElement(namespaceURI, localName, qName);

        // Check after popping the stack so we don't erroneously think we
        // are our own extension namespace...
        boolean inExtension = inExtensionNamespace();

        int entryType = -1;
        Vector entryArgs = new Vector();

        if (namespaceURI != null
                && (extendedNamespaceName.equals(namespaceURI))
                && !inExtension) {

            String popURI = (String) baseURIStack.pop();
            String baseURI = (String) baseURIStack.peek();

            if (!baseURI.equals(popURI)) {
                entryType = Catalog.BASE;
                entryArgs.add(baseURI);

                debug.message(4, "(reset) xml:base", baseURI);

                try {
                    CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
                    catalog.addEntry(ce);
                } catch (CatalogException cex) {
                    if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
                        debug.message(1, "Invalid catalog entry type", localName);
                    } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
                        debug.message(1, "Invalid catalog entry (rbase)", localName);
                    }
                }
            }
        }
    }
}
